Stamped mail limit is 13 oz.

Self-stampers should be aware that new U.S. Postal Service rules limit the weight of stamped mail to 13 ounces for security reasons.

Self-stampers should be aware that new U.S. Postal Service rules limit the weight of stamped mail to 13 ounces for security reasons.

The change was made a month ago, but some post offices do not yet have stickers advertising the fact on their curb-side boxes.

Kathy Lucas, spokeswoman for the Postal Service's Columbus District, said the stickers are still coming in, and as soon as they are available will be shipped to rural offices.

The change was prompted for airplane security and resulted from discussions between postal officials and members of the Federal Aviation Administration and Department of Homeland Security, Lucas said.

She said almost 1 million pieces of stamped mail a day are postmarked at the district's distribution center near Port Columbus.

"Something that weighs less is less likely to contain hazardous material," Lucas said.

The limit is for stamped mail only, as metered mail can be tracked back to its sender. Customers who stamp a package weighing more than 13 ounces will have it returned to them with a sticker explaining the new rule, Lucas said.

Anyone wishing to send heavier packages can do so at a post office or by printing shipping labels online at usps.com.